Please help! i will give brainliest!

What is the solution to the equation in the & show work i’m very

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. when the check comes, it says they also need to pay $3.99 in sales tax. what percentage of the subtotal is the sales tax

Present age of man is 45 years, 5 years back his age was 4 times age of his son what is present age of his son?